Mosquito sex combats disease

CORNELL (US) —The intricate sex life of the mosquito may hold clues to controlling diseases like the dengue and yellow fevers, and the West Nile virus.

Researchers have identified 145 proteins from male Aedes aegypti mosquitoes’ sperm and seminal fluid that are transferred during sex and may alter female egg production, feeding patterns, and receptivity to further mating.

There is currently no effective treatment for dengue fever, a potentially lethal infection that affects millions of people each year.

The research is reported in the journal PLoS Neglected Tropical Diseases.

“By distinguishing between male-derived and female-derived proteins within the female reproductive tract, we can begin to determine which male-derived proteins affect the behavior and physiology of the females, and how they do it,” says Laura Sirot, formerly a research associate at Cornell University and now an assistant professor of biology at the College of Wooster.

While previous research identified some reproductive proteins produced in male mosquitoes, “this is the first study to identify the male proteins that are actually transferred to the female” during mating, says Mariana Wolfner, professor of molecular biology and genetics at Cornell.

Researchers found 93 seminal fluid proteins and 52 sperm proteins in the females that might eventually be used to develop innovative mosquito control strategies, such as reducing egg production and curbing the female’s appetite for blood, which could ultimately reduce the spread of mosquito-borne, life-threatening illnesses.

Next, the team will determine which proteins have major effects on the female’s physiology by generating in the lab mosquitoes that fail to make each of these proteins, mate those males with females, and observe whether the females’ responses are perturbed.

“This is an exciting new avenue for identifying ultimate targets to reduce mosquito vector populations,” says Laura Harrington, associate professor of entomology.

“Ultimately, we plan to select the most promising candidates [proteins] as chemical targets or as a focus for the development of other methods for vector control.”

The study was funded by the National Institutes of Allergy and Infectious Diseases within the National Institutes of Health.

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